Emergency stop circuit

Abstract

The invention discloses an emergency stop circuit, which comprises an emergency stop switch; the emergency stop switch is connected with the first relay circuit, and the first relay circuit is connected with the contactor; the emergency stop switch is connected with the second relay circuit, and the first relay circuit and the second relay circuit are connected in parallel and interlocked; the second relay circuit is connected with an emergency stop signal output circuit; by designing the interlocking circuit formed by the emergency stop switch and the two relay circuits, the safety requirement of the emergency stop circuit is met, the action time of the relays is restrained, the abnormal condition of the emergency stop circuit is effectively filtered, the emergency stop reliability is improved, and meanwhile, the emergency stop signal output circuit is designed, so that the emergency stop signal output is accurate and reliable.

Description

Technical Field

[0001] The invention relates to the technical field of protection circuits, and in particular to an emergency stop circuit. Background Art

[0002] In modern industrial automation and intelligent manufacturing systems, the design of emergency stop circuits is crucial. It can quickly cut off the power supply in an emergency to ensure the safety of personnel and equipment. Usually, the emergency stop system includes an emergency stop switch, an emergency stop circuit and a contactor. The emergency stop switch cooperates with the emergency stop circuit to control the contactor, and the contactor controls the on and off of the strong current.

[0003] The emergency stop circuit uses an emergency stop switch directly connected in series to the contactor coil for control, which has low safety. Alternatively, a relay is added between the emergency stop switch and the contactor to improve safety, but the relay will bring new risks. If the relay is damaged or abnormal, the emergency stop may not be able to disconnect the contactor immediately. If the contactor is controlled by 220V, there is also a risk of electric shock. Summary of the invention

[0004] The purpose of the present invention is to solve the shortcomings in the prior art and to propose an emergency stop circuit.

[0005] In order to achieve the above object, the present invention adopts the following technical solution: an emergency stop circuit, comprising:

[0006] Emergency stop switch;

[0007] The emergency stop switch is connected to a first relay circuit, and the first relay circuit is connected to a contactor;

[0008] The emergency stop switch is connected to a second relay circuit, and the first relay circuit and the second relay circuit are interlocked in parallel;

[0009] The second relay circuit is connected to the emergency stop signal output circuit.

[0010] As a further description of the above technical solution: the first relay circuit includes a first normally open switch, the first normally open switch is connected to the anode of the first diode, and the cathode of the first diode is connected to the first relay and the first normally closed switch.

[0011] As a further description of the above technical solution: a first capacitor, a first resistor and a second diode are connected in parallel between the first diode and the first relay, one side of the first resistor is connected to the positive electrode of the first light-emitting diode, and the negative electrode of the first light-emitting diode is grounded.

[0012] As a further description of the above technical solution: the second relay circuit includes a second normally open switch, the second normally open switch is connected to the positive electrode of the third diode, the negative electrode of the third diode is connected to the second relay and the second normally closed switch, and the first normally closed switch is connected in parallel with the second normally closed switch.

[0013] As a further description of the above technical solution: a second capacitor, a second resistor and a fourth diode are connected in parallel between the third diode and the second relay, one side of the second resistor is connected to the positive electrode of the second light-emitting diode, and the negative electrode of the second light-emitting diode is grounded.

[0014] As a further description of the above technical solution: one side of the emergency stop switch is connected to the first normally open switch and the second normally open switch, and the other side is connected to the first power supply. The emergency stop switch is a normally closed switch. The emergency stop switch is connected to the positive electrode of the fifth diode, and the negative electrode of the fifth diode is connected to the contactor.

[0015] As a further description of the above technical solution: the contactor includes a coil, which is connected in series with a third normally open switch and a fourth normally open switch and is connected to a second power supply, and a feedback contact is provided on one side of the coil and is connected to the cathode of the fifth diode.

[0016] As a further description of the above technical solution: the emergency stop signal output circuit includes a first photocoupler and a second photocoupler, the first photocoupler is connected to the anode of the first diode through a third resistor, and the second photocoupler is connected to the anode of the third diode through a fourth resistor.

[0017] As a further description of the above technical solution: the second photocoupler is connected to the fifth resistor, the fifth resistor is connected to the base of the transistor, the collector of the transistor is connected to the cathode of the third light-emitting diode, the anode of the third light-emitting diode is connected to the sixth resistor, the sixth resistor is connected to the third power supply, and the emitter of the transistor is grounded.

[0018] As a further description of the above technical solution: a third normally closed switch and a fourth normally closed switch are connected in parallel between the emitter and the base of the transistor.

[0019] The above technical solution has the following advantages or beneficial effects:

[0020] By designing an interlocking circuit formed by an emergency stop switch and two relay circuits, not only the safety requirements of the emergency stop circuit are met, but also the relay action time is constrained, abnormal conditions of the emergency stop circuit are effectively filtered out, and the reliability of the emergency stop is improved. At the same time, the design of the emergency stop signal output circuit also makes the emergency stop signal output accurate and reliable. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 This is a circuit schematic diagram of the emergency stop circuit proposed by the present invention.

[0022] Legend:

[0023] 1. Emergency stop switch; 11. Fifth diode; 2. First relay circuit; 21. First normally open switch; 22. First diode; 23. First relay; 24. First normally closed switch; 25. First capacitor; 26. First resistor; 27. Second diode; 28. First light emitting diode; 3. Second relay circuit; 31. Second normally open switch; 32. Third diode; 33. Second relay; 34. Second normally closed switch; 35. Second capacitor; 36. Second resistor; 37. Fourth diode; 38. Second light emitting diode; 4. Contactor; 41. Coil; 42. Third normally open switch; 43. Fourth normally open switch; 5. Emergency stop signal output circuit; 51. First photocoupler; 52. Second photocoupler; 53. Third resistor; 54. Fourth resistor; 55. Fifth resistor; 56. Transistor; 57. Third light emitting diode; 58. Sixth resistor; 59. Third normally closed switch; 510. Fourth normally closed switch. DETAILED DESCRIPTION

[0024] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0025] Reference Figure 1 An embodiment of the present invention is as follows: an emergency stop circuit comprises: an emergency stop switch 1; the emergency stop switch 1 is connected to a first relay circuit 2, and the first relay circuit 2 is connected to a contactor 4; the emergency stop switch 1 is connected to a second relay circuit 3, and the first relay circuit 2 is interlocked with the second relay circuit 3 in parallel; the second relay circuit 3 is connected to an emergency stop signal output circuit 5.

[0026] In this embodiment, the first relay circuit 2 and the second relay circuit 3 are designed to be interlocked and then connected to the contactor 4. When emergency stop control is required, the contactor 4 can be disconnected immediately, and the control of the contactor 4 can be guaranteed even if one of the relays is abnormal. By designing the interlocking circuit formed by the emergency stop switch 1 and the two relay circuits, not only the safety requirements of the emergency stop circuit are met, but also the relay action time is constrained, the abnormal situation of the emergency stop circuit is effectively filtered, and the reliability of the emergency stop is improved. At the same time, the design of the emergency stop signal output circuit 5 also makes the emergency stop signal output accurate and reliable.

[0027] The first relay circuit 2 includes a first normally open switch 21, the first normally open switch 21 is connected to the positive electrode of the first diode 22, and the negative electrode of the first diode 22 is connected to the first relay 23 and the first normally closed switch 24. A first capacitor 25, a first resistor 26, and a second diode 27 are connected in parallel between the first diode 22 and the first relay 23, one side of the first resistor 26 is connected to the positive electrode of the first light-emitting diode 28, and the negative electrode of the first light-emitting diode 28 is grounded.

[0028] In this embodiment, the first diode 22 is a Schottky diode. When the first relay 23 is powered on and energized, the second normally closed switch 34 is disconnected, and the first capacitor 25 is used for charging and discharging to achieve delayed action constraint of the first relay 23 .

[0029] The second relay circuit 3 includes a second normally open switch 31, the second normally open switch 31 is connected to the positive electrode of the third diode 32, the negative electrode of the third diode 32 is connected to the second relay 33 and the second normally closed switch 34, and the first normally closed switch 24 is connected in parallel with the second normally closed switch 34; a second capacitor 35, a second resistor 36 and a fourth diode 37 are connected in parallel between the third diode 32 and the second relay 33, one side of the second resistor 36 is connected to the positive electrode of the second light-emitting diode 38, and the negative electrode of the second light-emitting diode 38 is grounded.

[0030] In this embodiment, the third diode 32 is a Schottky diode. When the second relay 33 is powered on and energized, the first normally closed switch 24 is disconnected to achieve interlocking of the first relay circuit 2 and the second relay circuit 3. The second capacitor 35 is used for charging and discharging to achieve delayed action constraint of the second relay 33. The performance parameters of the first relay 23 and the second relay 33 are consistent.

[0031] One side of the emergency stop switch 1 is connected to the first normally open switch 21 and the second normally open switch 31, and the other side is connected to the first power supply V1. The emergency stop switch 1 is a normally closed switch. The emergency stop switch 1 is connected to the positive electrode of the fifth diode 11, and the negative electrode of the fifth diode 11 is connected to the contactor 4.

[0032] In this embodiment, the fifth diode 11 is a Schottky diode, the first power supply supplies power to the first relay circuit 2 and the second relay circuit 3, which is 24V, and the emergency stop switch 1 is a normally closed switch, providing electrical signal input for the first relay circuit 2 and the second relay circuit 3.

[0033] The contactor 4 includes a coil 41 , which is connected in series with a third normally open switch 42 and a fourth normally open switch 43 and is connected to a second power supply V2 . A feedback contact is provided on one side of the coil 41 and is connected to the cathode of the fifth diode 11 .

[0034] In this embodiment, the contactor 4 includes a coil 41, a third normally open switch 42 and a fourth normally open switch 43 connected in series, when the first relay circuit 2 and the second relay circuit 3 are powered on, the third normally open switch 42 and the fourth normally open switch 43 are connected, and the second power supply V2 is the driving power supply of the contactor 4.

[0035] The emergency stop signal output circuit 5 includes a first photocoupler 51 and a second photocoupler 52. The first photocoupler 51 is connected to the positive electrode of the first diode 22 through a third resistor 53, and the second photocoupler 52 is connected to the positive electrode of the third diode 32 through a fourth resistor 54; the second photocoupler 52 is connected to a fifth resistor 55, and the fifth resistor 55 is connected to the base of a transistor 56. The collector of the transistor 56 is connected to the negative electrode of the third light-emitting diode 57, and the positive electrode of the third light-emitting diode 57 is connected to a sixth resistor 58. The sixth resistor 58 is connected to a third power supply V3, and the emitter of the transistor 56 is grounded; a third normally closed switch 59 and a fourth normally closed switch 510 are connected in parallel between the emitter and the base of the transistor 56.

[0036] In this embodiment, the first photocoupler 51 and the second photocoupler 52 are connected to the first relay circuit 2 and the second relay circuit 3 through the third resistor 53 and the fourth resistor 54. When the first relay 23 and the second relay 33 are both connected, the first photocoupler 51 and the second photocoupler 52 are turned on, so that the third power supply V3 supplies power to the emergency stop signal output circuit 5, and the signal output port is set between the cathode of the third light-emitting diode 57 and the collector of the transistor 56.

[0037] The first relay 23 is actuated to control the first normally open switch 21, the second normally closed switch 34, the third normally closed switch 59 and the fourth normally open switch 43 to actuate;

[0038] The second relay 33 is actuated to control the second normally open switch 31 , the first normally closed switch 24 , the fourth normally closed switch 510 , and the third normally open switch 42 to operate.

[0039] Working principle:

[0040] At the beginning of power-on, the feedback electric shock of the emergency stop switch 1 and the contactor 4 is in the closed state, the contactor 4 is not powered on and attracted, and the strong current is not connected. The current of the first power supply charges the first capacitor 25 and the second capacitor 35 through the emergency stop switch 1, the fifth diode 11, the feedback contact of the contactor 4, the first normally closed switch 24, and the second normally closed switch 34. The voltage across the first capacitor 25 and the second capacitor 35 continues to rise and reaches the relay coil pull-in voltage. The coils of the first relay 23 and the second relay 33 are pulled in, so that the first normally closed switch 24 and the second normally closed switch 34 are disconnected and the first normally open switch 21 and the second normally open switch 31 are closed. From the time when the first normally closed switch 24 and the second normally closed switch 34 are disconnected to the time when the first normally open switch 21 and the second normally open switch 31 are closed, the first capacitor 25 and the second capacitor 35 continuously supply power to the coils of the first relay 23 and the second relay 33, so as to prevent the first normally closed switch 24 and the second normally closed switch 34 from losing power due to the disconnection of the coils, causing the first normally closed switch 24 and the second normally closed switch 34 to return to their original state. Afterwards, the current of the first power supply passes through the emergency stop switch 1 and respectively supplies power to the coils of the first relay 23 and the second relay 33 through the first normally open switch 21, the second normally open switch 31, the first diode 22, and the third diode 32, forming a stable state. The third normally open switch 42 and the fourth normally open switch 43 are closed, and the contactor 4 is closed under the drive of the second power supply, so that strong electricity can be conducted.

[0041] After the emergency stop switch is pressed, the first power supply cannot be input to the coils of the first relay 23 and the second relay 33 through the emergency stop switch 1, the third normally open switch 42 and the fourth normally open switch 43 are disconnected, the contactor loses power and disconnects the high power, and the third normally open switch 42 and the fourth normally open switch 43 constitute the output interface of the entire emergency stop circuit, which is used to control the contactor 4 of the subsequent stage.

[0042] During the initial power-on period, the first normally closed switch 24 controls the first relay 23 coil, and the second normally closed switch 34 controls the second relay 33. The two relays are interlocked. Because the parameters of the two relays are consistent, when powered on, the first relay 23 and the second relay 33 will be energized almost simultaneously.

[0043] If there is an abnormality, for example, the first relay 23 has a delayed closing action, and the first relay 23 has not yet acted when the second relay 33 is closed, the first normally closed switch 2 becomes open, and the coil of the first relay 23 will not receive current input, and will no longer be able to close. The contactor 4 will also no longer be driven, and strong electricity cannot be conducted.

[0044] If the first relay 23 has contacts sintered, it will be the same as the above situation and the contactor 4 cannot be driven normally.

[0045] If the second relay 33 has an abnormality, it will be similar to the abnormality of the first relay 23 and the contactor cannot be driven normally.

[0046] The emergency stop signal output circuit 5 is used to output the emergency stop status signal to the subsequent stage for convenient monitoring and processing. The circuit operation logic is as follows:

[0047] The inputs of the first photocoupler 51 and the second photocoupler 52 are connected to the first normally open switch 21 and the second normally open switch 31 through the third resistor 53 and the fourth resistor 54. Only when the first relay 23 and the second relay 33 are both energized, the first photocoupler 51 and the second photocoupler 52 can be turned on. The output pins of the first photocoupler 51 and the second photocoupler 52 are connected in series to the fifth resistor 55. This makes it possible for the current of the third power supply to flow through the fifth resistor 55 to the first power supply only when the first photocoupler 51 and the second photocoupler 52 are both turned on, so that the first power supply is turned on, the third light-emitting diode 57 is lit, and the output emergency stop signal changes from a high level to a low level, indicating that it is now in a normal state.

[0048] After the emergency stop switch 1 is disconnected, there is no current input to the first photocoupler 51 and the second photocoupler 52, the output stage is not conducting, and then the first power supply is not conducting, the third light emitting diode 57 is extinguished, and the output emergency stop signal is set to a high level, indicating that it is now in an emergency stop state.

[0049] The third normally closed switch 59 and the fourth normally closed switch 510 are safety redundant designs for the emergency stop signal. As long as any one of the contacts is closed, the first power supply will not be turned on and the output emergency stop signal will be set to a high level.

[0050] Finally, it should be noted that the above is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, it is still possible for those skilled in the art to modify the technical solutions described in the aforementioned embodiments or to make equivalent substitutions for some of the technical features therein. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. An emergency stop circuit, characterized in that: include: Emergency stop switch (1); The emergency stop switch (1) is connected to a first relay circuit (2), and the first relay circuit (2) is connected to a contactor (4); The emergency stop switch (1) is connected to the second relay circuit (3), and the first relay circuit (2) and the second relay circuit (3) are connected in parallel and interlocked; The second relay circuit (3) is connected to the emergency stop signal output circuit (5).

2. The emergency stop circuit according to claim 1, characterized in that: The first relay circuit (2) comprises a first normally open switch (21), wherein the first normally open switch (21) is connected to the positive electrode of a first diode (22), and the negative electrode of the first diode (22) is connected to the first relay (23) and the first normally closed switch (24).

3. The emergency stop circuit according to claim 2, characterized in that: A first capacitor (25), a first resistor (26) and a second diode (27) are connected in parallel between the first diode (22) and the first relay (23); one side of the first resistor (26) is connected to the positive electrode of the first light-emitting diode (28); and the negative electrode of the first light-emitting diode (28) is grounded.

4. The emergency stop circuit according to claim 2, characterized in that: The second relay circuit (3) comprises a second normally open switch (31), the second normally open switch (31) being connected to the positive electrode of a third diode (32), the negative electrode of the third diode (32) being connected to the second relay (33) and the second normally closed switch (34), and the first normally closed switch (24) and the second normally closed switch (34) being connected in parallel.

5. The emergency stop circuit according to claim 4, characterized in that: A second capacitor (35), a second resistor (36) and a fourth diode (37) are connected in parallel between the third diode (32) and the second relay (33); one side of the second resistor (36) is connected to the positive electrode of the second light-emitting diode (38); and the negative electrode of the second light-emitting diode (38) is grounded.

6. The emergency stop circuit according to claim 4, characterized in that: One side of the emergency stop switch (1) is connected to the first normally open switch (21) and the second normally open switch (31), and the other side is connected to a first power supply. The emergency stop switch (1) is a normally closed switch. The emergency stop switch (1) is connected to the positive electrode of a fifth diode (11), and the negative electrode of the fifth diode (11) is connected to the contactor (4).

7. The emergency stop circuit according to claim 1, characterized in that: The contactor (4) comprises a coil (41), the coil (41) is connected in series with a third normally open switch (42) and a fourth normally open switch (43), and is connected to a second power supply; a feedback contact is provided on one side of the coil (41) and is connected to the cathode of the fifth diode (11).

8. The emergency stop circuit according to claim 4, characterized in that: The emergency stop signal output circuit (5) comprises a first photocoupler (51) and a second photocoupler (52), wherein the first photocoupler (51) is connected to the positive electrode of the first diode (22) via a third resistor (53), and the second photocoupler (52) is connected to the positive electrode of the third diode (32) via a fourth resistor (54).

9. The emergency stop circuit according to claim 8, characterized in that: The second photoelectric coupler (52) is connected to a fifth resistor (55), the fifth resistor (55) is connected to the base of a transistor (56), the collector of the transistor (56) is connected to the cathode of a third light-emitting diode (57), the anode of the third light-emitting diode (57) is connected to a sixth resistor (58), the sixth resistor (58) is connected to a third power supply, and the emitter of the transistor (56) is grounded.

10. The emergency stop circuit according to claim 9, characterized in that: A third normally closed switch (59) and a fourth normally closed switch (510) are connected in parallel between the emitter and the base of the triode (56).

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